JPS60115333A - Burring working method - Google Patents

Abstract

PURPOSE:To execute working by a space of one process portion in case of a progressive die by one die, by forming an upper die and a lover die by a specified structure, and three works of preliminary drawing, prepared hole punching and burring in one process on the same axis, in a titled working by a press machine. CONSTITUTION:A die 41 and a punch 43 are fixed to an upper die a stripper 45 is attached through a spring 47, a punch 42 is fixed to a lower die, and a stipper 44 is attached through a spring 46. A plate to be worked A is placed on the lower die, the upper die is made to descend, and when the plate A reaches on the punch 42, it is held by the stipper 45, a preliminary drawing B is started in the upper direction by the punch 42, the punch 43 contacts to the plate A and the drawing B is ended. Subsequently, the plate A is made to descend together with the upper die, the punch 42 becomes a die, a prepared hole C is punched by the punch 43, and simultaneously, burring is executed in the upper direction by the punch 42.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to press working of sheet metal, and in particular, involves heating a flat plate and protruding a punch to form a hole flange.
It relates to a method of so-called burring processing.

Background of the technology: Sheet metal products are used in large numbers as constituent members of various structures. When the workpiece is a mass-produced product, it is usually processed by press working, which provides uniform processing and reduces processing costs.

If this workpiece is to be tapped to fasten a screw or drilled to lock or engage another member, the thickness of the workpiece may not be sufficient to meet the required dimensions. In such cases, burring is often performed to erect a hole flange to ensure the required dimensions.

(C) Prior art and problems Figure 1 is a diagram showing the steps of an example of conventional burring processing (al~) (C), and Figure 2 is a diagram showing an example of the processing method ( a) (bl (In C1, A is a board, 'B
is preliminary drawing, C is lower heat, D is hole flange, h is hole flange height, 11.21.31 is die, 12.22.32 is punch, 13.23.33 is stripper, 14.24.
34 each indicates a spring.

In Fig. 1, the first preliminary calibration B shown in Fig. Cal is a process performed when the hole flange height h is increased relative to the thickness of the plate to be processed, and h is It can be omitted if it is small. The punching of the pilot hole C shown in Figure (BL) is a process performed to give the tip of the hole flange D a smooth shape without cracks, and finally the hole flange D shown in Figure (C1) is formed by burring.

FIG. 2 shows a processing method in which these steps are performed by press working, and FIGS. (a), (b), and (C1 correspond to the steps in FIG. 1, respectively. In each process, the plate A is aligned and placed on the die 11.21.31 fixed to the lower mold, and the punch 12.22.32 fixed to the upper mold is lowered from above to process it. In the figure, the punches 12, 22, 32 are shown in a lowered state.

At this time, a stripper 13.23.33 is attached to the upper mold via a spring 14.24.34 and also serves as a guide for the tip of the punch 12.22.32, and this is lowered first to hold down the plate A. , often suppresses the occurrence of unnecessary deformation of plate A.

The burring processing method with this configuration has the drawback that the mold needs to be mounted and the number of operations is three times, and the production cost is not low. When it is made into a mold, it is usually combined with other processing, and this burring process requires space for three processes, which has the disadvantage that the progressive mold becomes large.

(d) Purpose of the Invention In view of the above-mentioned drawbacks of the conventional art, the purpose of the present invention is to sequentially perform the burring process, which consists of preliminary drawing, undercooking, and burring, to form a hole flange with a large flange height, using a single mold. It is an object of the present invention to provide a processing method that requires only one step of space for mold feeding and can complete the processing in -1 operations.

(el Structure of the Invention The above object is to press down the workpiece plate material with a die fixed to the upper die during the downward stroke of the press machine, and in that stroke, first perform preliminary drawing with the first punch fixed to the lower die. Then, the first punch is used as a die and a second punch fixed to the upper mold is used to pierce the lower part smaller than the first punch diameter, and the first punch is further used to perform burring. This is achieved by a burring method.

According to the present invention, it is desirable that the tip of the first punch be tapered stepwise, that the preliminary drawing be trapezoidal, and that the burring be done in multiple stages.

By doing this, the three processes of preliminary drawing, pilot hole punching, and burring are performed in one process on the same axis, so only one mold is required, and the space for one process is sufficient for progressive molds. Needless to say, it can be completed in one operation.

However, the trapezoid shape in the preliminary drawing process is easy to process, and the multi-stage burring increases the clearance when enlarging the pilot hole to make the process straightforward, and in the final burring process, it enables stable ironing process and The flow of fire is on the outside of the hole flange, suppressing material cracking, and helping to increase the flange height.

ffl Embodiments of the Invention Below, embodiments of the present invention will be explained with reference to the drawings. The same reference numerals indicate the same objects throughout the figures.

FIG. 3 is a diagram showing an embodiment of the burring method according to the present invention.
is a die, 42.43 is a punch, 44.45↓ is a stripper, 46.47 is a spring, and a-y f are dimensions, respectively.

Figure fa) in Figure 3 shows the configuration of the mold to be processed by the processing method of the present invention in a state before processing,
Tel (d) shows each process of preliminary drawing, undercooking, and burring.
This roughly corresponds to (C).

In Figure (al), a die 41 and a punch 43 are fixed to the upper die, and a stripper 45 is attached via a spring 47.A punch 42 is fixed to the lower die, and a stripper 44 is attached to a spring 46. It is installed through.

Plate A, which is a plate material to be processed, is placed on the lower die, the upper die is lowered, and the plate A is lowered while being pressed onto the stripper 44 by the die 41. When plate A reaches the top of punch 42,
While pressing with the stripper 45, preliminary drawing is started upward with the punch 42, which is the -th punch, and when the punch 43 comes into contact with the plate A, the state shown in Figure 1) is reached, and the preliminary drawing B ends. Here, the tip of the punch 42 is made tapered stepwise as shown in the figure, the clearance with the die 41 is made larger than the thickness of the plate A, and the shape of the preliminary blank B is made into a trapezoid, so it is impossible to draw it. There is no.

Next, the plate A is lowered together with the upper mold, and as shown in Figure fe), the punch 42 is used as a die and the second punch 43 is used to punch out the pilot hole C downward, and at the same time, the punch 42 is used to punch the pilot hole C downward. Start barring. Burling is punch 4
The one-stage taper of No. 2 provides two-stage processing, and in the first stage, the pilot hole C can be easily enlarged due to the clearance. However, when the pilot hole C on the top surface of the plate A is removed, the hole C comes to the outside of the hole flange D, which prevents the material from cracking. In the second stage, which is the final burring shown in Figure (dl), stable ironing becomes possible, helping to increase the flange height.

As described above, according to the processing method of the present invention, the three processes of preliminary drawing, lower firing, and burring are performed in one stroke on the same axis, so there is only one mold, and in the progressive mold. Needless to say, the space needed for one process is sufficient, and the process can be completed in one go.

The inventors calculated each dimension of a-r shown in the figure (al) as a=16.5wm, 1)=16. (hmφ, C=1
4. O'mφ, d = 4.0m, e = 0.3m
By setting RXf = 10.9 mmφ and processing an aluminum plate with a thickness of 0.4 m, it was possible to obtain a clean hole flange with a flange height h = 4.0 wm. Also, punch 4
Add a tapered part to the tip of 2, f = 7.9m
It was also possible to obtain a flange height h=5.5 m by setting the diameter to mφ.

(a) Effects of the Invention As explained above, according to the configuration of the present invention, the burring process that consists of preliminary drawing, pilot hole punching, and burring to form a hole flange with a large flange height can be performed with one mold. , In progressive molding, the space required for one process is sufficient.
- It is possible to provide a processing method that allows processing to be completed in one operation, and has the effect of reducing production costs and suppressing the size and size of the mold in progressive mold 4. be.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a diagram (a) showing the process of an example of conventional burring processing (bl tc+, Fig. 2 is a diagram Ta showing an example of the processing method) ( b) (C) and Fig. 3 are diagrams (al (b) (C) (d)) showing an example of the burring processing method according to the configuration of the present invention. In the drawings, A is a plate and B is a preliminary plate. Aperture, C is the prepared hole, D is the hole flange, a - f is the dimension, h is the hole flange height, 1
1.21.31.41 is die, 12.22.32.42
．． 43 is punch, 13.23.33.44.45 is striso. 14.24.34.46.47 indicate the springs, respectively.

Claims (2)

[Claims] (1) During the downward stroke of the press machine, the die fixed to the upper die presses down the workpiece plate material, and in this process, first, the first punch fixed to the lower die performs preliminary drawing, and then the second punch is fixed to the lower die. A burring processing method characterized in that a first punch is used as a die and a second punch fixed to an upper mold is used to punch out a bottom hole smaller than the diameter of the first punch, and further, burring is performed using the first punch. (2) The tip of the first punch is tapered stepwise, the preliminary drawing is trapezoidal, and the burring is performed in multiple stages.
burring method described in ).